The Caledonian pine forest in Scotland consists of birch, juniper and Scots pine, which are all adapted to cope with intense cold weather. The birch does it by shedding its leaves and shutting down all systems for the winter. The pine and the juniper, on the other hand, have evolved fine needles that lose much less moisture than other floppier leaves. Also, their sap contains the plant-equivalent of anti-freeze so the needles do not go rock-solid in winter. If climate change increases Britain's temperatures, then these forests may be doomed.